Parallel & Discharge rate

[gartman]

I thought Jay's intuitive answer above covered your question, but if not could you please give a bit more information concerning what you are looking for.

i.e.
Motor operating voltage
Boat size
Desired use
etc.

I'm looking for a good lipo for a 26" v hull 120 esc and a 88 amp motor. Thanks

[Diesel6401]

I'm looking for a good lipo for a 26" v hull 120 esc and a 88 amp motor. Thanks

May I ask what size motor 380 or 540 s/l/xl can etc... and also KV rating?

[gartman]

May I ask what size motor 380 or 540 s/l/xl can etc... and also KV rating?

540L 3511kv

[Diesel6401]

You could run a single pack. A single 2s 5000mah 30C or 40C will do the trick or even 4000mah 30c or 40c will work to. All those pack will handle the amp draw. I like the 5000mah 40c's myself. A single 2s for sport or even 3s for craziness. JMO

[gartman]

You could run a single pack. A single 2s 5000mah 30C or 40C will do the trick or even 4000mah 30c or 40c will work to. All those pack will handle the amp draw. I like the 5000mah 40c's myself. A single 2s for sport or even 3s for craziness. JMO

Im gona try two 3s 2200mah at 25c 50 burst

[Diesel6401]

Lot of weight but may work for you. Don't forget with those higher KV motors you will need a smaller prop. Keep it under 40mm. 35mm-38mm range IMO

[gartman]

Lot of weight but may work for you. Don't forget with those higher KV motors you will need a smaller prop. Keep it under 40mm. 35mm-38mm range IMO

O.K. Thanks, and Thanks to every one who has helped me. This Forum is great

[keithbradley]

Just to make sure this is clear because people ALWAYS get confused on this...
Simply put, when parallel connecting two batteries, dishcharge rate doubles, but c rating does not.
They are not the same thing, and thats what causes a lot of confusion. Discharge rate is the amount of current a pack (or packs) is capable of safely discharging. C rating is a number given to packs to help you determine what the discharge rate is. C rating never doubles. If your pack is 40C/5000mah and you run another pack of the same rating in parallel, you will have double the discharge rate (400A), but the C rating is still 40C.

[chuff]

See also this thread.
http://forums.offshoreelectrics.com/...ad.php?t=15696
Chris

[gartman]

I thought C rating is the discharge rate.

[chuff]

Yes, confusing....

Think of it like this:

Imagine a PACK has the following printed on the label:

5000 mAhr - that is how big the "fuel tank" is. It contains 5 amphours of energy when fully charged.
30 C - that means that the manufacturer would have us believe it is SAFE to draw 30 times 5000 milliamps out of the pack (ie 30 x 5000 - 150,000 milliamps or 150 amps)

If you then wire two packs up in Parallel, you have 10 Amphours in the fuel tank and according to the manufacturer you could safely attach the pair to a motor demanding 300 amps. 3 in parallel and you could hook them to a motor demanding 450 amps, and so-on.

" 1C" originally was defined as the current that will theoretically totally exhaust a battery in 1 hour (or fully charge it in 1 hour).

Chris